Revert "Pin requests-file during typecheck"

The types are fixed in 3.0.1.

This reverts commit 25643e4.

Author: john-kurkowski

tldextract/suffix_list.py

@@ -9,7 +9,7 @@
 from typing import cast
 
 import requests
-from requests_file import FileAdapter  # type: ignore[import-untyped]
+from requests_file import FileAdapter
 
 from .cache import DiskCache
 

tox.ini

@@ -19,7 +19,4 @@ extras = testing
 [testenv:typecheck]
 basepython = python3.9
 commands = mypy --show-error-codes scripts tldextract tests
-deps =
-    # Exclude 3.0 due to type error. Await fix in https://codeberg.org/dashea/requests-file/pulls/43
-    requests-file>=1.4,<3.0
 extras = testing